KR20120072613A - Oxidation pond for treating acid mine drainage - Google Patents

Abstract

PURPOSE: An oxidizing tank for treating mine waste water is provided to accelerate the precipitating reaction of iron in the mine waste water by increasing the pH values of the mine waste water. CONSTITUTION: An oxidizing tank(100) for treating mine waste water includes an inlet(11), a waste bath(12), and an outlet(13). The mine waste water is introduced through the inlet. The mine waste water is maintained in the water bath. The mine waste water is discharged through the outlet. While the mine waste water is maintained in the water bath, iron in the mine waste water is oxidized and precipitated. A neutralizing member(30) is installed at the water bath. The neutralizing member increases the pH values of the mine waste water to accelerate the precipitating reaction of iron. The neutralizing member is hung in the underwater of the water bath. The neutralizing member is natural limestone lump. A dispersion guiding member is installed at the front side of the inlet.

Description

Oxidation pond for treating acid mine drainage

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for reducing environmental pollution, and more particularly, to an oxidation tank used in a passive treatment method for treating acid mine drainage discharged from abandoned mines.

Oxidation tanks used in the passive treatment method of AMD to purify acid mine drainage are dissolved oxygen and atmospheric oxygen that aerated ferric iron contained in mine drainage by holding mine drainage for a certain time. It is a water tank that induces oxidation reaction and precipitates with iron oxide.

The most important design element in the oxidizing tank is the residence time of mine drainage, and generally the residence time of mine drainage is defined as 48 hours or more. Design criteria of Article oxide is the nominal residence time there and defining the inflow conditions of the mine drainage, based on the area, i.e. the contact area by regulating a flow rate of 1L / sec per 100m ² divided by the flow rate of introducing the oxidizing tank total volume in contact with oxygen I design it as a standard.

The oxidation tank installed in Korea for the purpose of treating acid mine drainage is shown in the photograph of FIG. Although the size and shape of most oxidizers depend on the surrounding location conditions and land prices, as shown in FIG. 1, the structure in the oxidizers is generally filled with mine drainage without any structure. The appearance of this oxidizer is the same throughout the world.

The flow pattern of the mine drainage flowing into the oxidizing tank varies depending on the size and shape of the oxidizing tank, the inlet and the outlet, and the flow rate. In order to visually grasp this type of flow, it is useful to include tracers in the mine drainage flowing into the inlet and analyze them by their flow paths and characteristics.

The evaluation for the conventional oxidizing bath was performed. That is, the flow pattern of the conventional oxidation tank was identified by using the food coloring Blue 2, which is harmless to the human body, the salt water was used to calculate the residence time, and the CTD-DIVER was used to measure the electrical conductivity. In the measurement method, a tracer (salt water) was introduced into the mine drainage inlet to measure the residence time, which is the time required for the mine drainage to reach the exit, and the diffusion range of the dye during that time.

As shown in the photograph of FIG. 2, the test target oxidizer was a sinter rod oxidizer located in Mungyeong-si, Gyeongsangbuk-do, having an octagonal shape of 14 m in width and 6 m in length, and a total depth of 1.5 m. The thickness of the sediment at the bottom of the oxidizer tank is currently 0.35 m and the average depth at the time of measurement is about 0.75 m, considering the 0.4 m height from the top of the oxidizer tank to the water surface. The inlet for mine drainage is installed as a 40cm inner pipe, and the water level inside the pipe is located about 0.15 m above the bottom of the inner diameter of the pipe. In addition, the exit structure is installed with a square concrete channel with a width of 0.4 m and a height of 0.5 m. The flow rate of mine drainage into the oxidizing tank is 86.4 m ³ / hr.

 As shown in the photo of Figure 3, the food coloring Blue 2 was injected into the inlet of the oxidation tank at a constant concentration, the result of determining the diffusion path of the dye with time is shown in the photo of FIG. As shown in the photograph of FIG. 4, after the dye injection, the dye showed a linear flow pattern connecting the inlet and the outlet and there was almost no flow to the surroundings. In the photograph of FIG. 4 there is a tendency to migrate around some, but this is considered diffusion due to the difference in concentration of the dye. As a result, the first time the dye was introduced to reach the exit was 35 minutes.

5 shows the change in electrical conductivity measured by DIVER installed at the inlet and outlet of the oxidizer tank after the brine is introduced into the oxidizer tank inlet. As shown in the table of FIG. 5, the time point at which the brine is introduced at the inlet of the coral reef is 139 seconds, and the time point at which the salt water first reaches the outlet to indicate the change in electrical conductivity is 400 seconds and the time to reach a constant electrical conductivity is 434 seconds. Therefore, the initial time for the brine to reach the outlet from the inlet is 261 seconds, the time required to reach a constant electrical conductivity is 295 seconds. Therefore, the time taken for the brine to be detected at the outlet is 4.35 minutes after the brine is introduced.

Figure 6 shows the results of performing the computational flow analysis to determine the flow characteristics of the mine drainage flowing into the Seokbong oxidation tank. As shown in Figure 6 (a), when looking at the velocity distribution in the Seokbong oxidation tank, the speed of the line from the inlet to the outlet appears the fastest. Looking at the longitudinal cross-sectional view of the speed distribution, the speed gradually expands to the bottom as it proceeds toward the exit. However, the higher speed is mainly located on the water surface.

As shown in (b) of FIG. 6, when the streamline distribution of the Seokbong Oxygen Tank is observed, the main flow section connecting the inlet and the outlet, which is a high speed region, and the left side and the right side, which are large vortices formed on the boundary, are represented by the stagnant region 2. Branch flow patterns can be identified.

And, the residence time of the stone rod oxidation tank is shown by FIG.6 (c). As shown in (c) of FIG. 6, the residence time shows that the mine drainage flowing along the straight line connecting the inlet and the outlet shows a very short residence time, while the mine drainage placed in the peripheral section except the above straight section has a high retention. Time represents. In other words, the section other than the above straight section is determined to be the most congested region, not the section in which the mine drainage flows.

Looking at the distribution of residence time in the cross section, it was found that the residence time decreases rapidly from the inlet to the outlet. Therefore, the main flow area of the oxidizer tank is shown as a straight line connecting the inlet and the outlet, and there is almost no flow at the deep part of the oxidizer tank during the inflow and outflow of the mine drainage and the mine drainage flows along the surface of the water.

As a result, the oxidation tank is divided into the main flow zone and the stagnation zone connecting the inlet and the outlet, so that the inflow mine drainage flows along the main flow zone, which is a specific route, and the remaining zone remains as the stagnant zone which does not participate in the flow. .

That is, since the introduced mine drainage does not flow to the entire oxidation tank but flows along a specific flow region, such a flow pattern drastically reduces the residence time of the mine drainage in the oxidation tank and uses the space inefficiently, thus serving as the main role of the oxidation tank. It can't be done. In addition, when the residence time of the mine drainage is shortened, there is a problem in that the precipitation reaction of the ferric iron through a sufficient contact with oxygen is lowered, thereby making subsequent treatment of the mine drainage difficult.

On the other hand, the reaction rate of the reaction in which the iron ions in the mine drainage are oxidized with oxygen is precipitated into the hydroxide, which has a deep relationship with the pH of the mine drainage. 7 is a graph showing a change in the reaction rate of the iron precipitation reaction with the change of pH. Referring to the graph of Figure 7, it can be seen that the reaction rate is rapidly increased toward the neutral in the vicinity of pH3.

Accordingly, there is a need for a specific technology capable of accelerating the precipitation of iron in the mine drainage using a change in pH as well as increasing the residence time of the mine drainage in the oxidation tank.

The present invention has been made to solve the above problems, and an object thereof is to provide an oxidation tank for treating mine drainage, which has an improved structure to accelerate the precipitation reaction of iron in the mine drainage by increasing the pH of the mine drainage.

Oxidation tank for mine drainage treatment according to the present invention for achieving the above object, the inlet and the inlet of the mine drainage,

According to the present invention ...

1 is a photograph showing the foreground of several oxidizers installed in Korea.
Figure 2 is a photograph taken from the domestic Seokbong oxidation tank from above.
3 is a photograph showing a state in which a diver is installed and a dye is added in an experiment for measuring residence time in an oxidizing tank.
Figure 4 is a photograph showing the diffusion of the dye and the tracer with time in the Seokbong oxidation tank.
5 is a table showing the change in electrical conductivity with time at the inlet and outlet of the Seokbong oxidation tank.
Figure 6 shows the results of the computational flow analysis of the flow characteristics of the mine drainage of the Seokbong Oxygen Tank, where velocity distribution is shown in (a), streamline distribution in (b) and residence time distribution in (c).
7 is a graph showing a change in the reaction rate of the iron precipitation reaction with the change of pH.
8 is a schematic plan view of an oxidation tank for mine drainage treatment according to a first embodiment of the present invention.
FIG. 9 is a schematic cross-sectional view taken along line VII-VII of FIG. 8.
10 is a schematic diagram for explaining a second embodiment of the present invention.
11 is a schematic diagram for explaining a third embodiment of the present invention.
12 is a schematic perspective view of the dispersion guide member shown in FIG. 8.
FIG. 13 is a photograph experimenting with the present invention, in which the dispersion guide member is installed in the stone rod oxidation tank (right side), and the photograph (left) in which the dispersion guide member is not installed.
14 is a photograph showing the final result of the experiment.
15 is a table showing a change in electrical conductivity with time at the inlet and outlet of the oxidation tank.
16 to 18 are schematic perspective views of different types of dispersion guide members.
19 is a schematic perspective view of another type of dispersion guide member.
20 is a photograph showing an experimental process of the dispersion guide member shown in FIG. 19 over time.
21 is a table showing the change in electrical conductivity with time at the inlet and outlet of the oxidation tank.

First, a brief description will be given of a mine drainage which is a treatment target of an oxidation tank for mine drainage treatment according to the present invention. Since mine drainage is generally acidic, it is commonly referred to as acid mine drainage (AMD). Acid mine drainage is formed when sulfide minerals such as pyrite (FeS2) and ferrite (FeS) exposed to the atmosphere are oxidized by reaction with oxygen and water, and have a low pH, resulting in acidity, iron, aluminum, manganese, etc. It is characterized by a high metal content.

The oxidation of pyrite is given by the following equations.

FeS ₂ + 7 / 2O _{2 ^{+ H 2 O → Fe 2 +}} + 2SO4 2 - + 2H +

Fe ^{2 +} + 1/4 O ₂ + H ⁺ → Fe ^{3 +} + 1/2 H ₂ O

Fe ^{3 +} + 3H ₂ O → Fe (OH) ₃ (s) + 3H ⁺

_{^{FeS 2 + Fe 3 + + 8H}} 2 O → 15Fe 2 + + 2SO4 2 - + 16H +

As shown in the above equation, pyrite is oxidized to generate iron ions and sulfate ions and to be acidified by hydrogen ions. These acid mine drainages have high mobility of toxic heavy metals due to their low pH, contaminating surrounding surface water and groundwater and destroying aquatic ecosystems. In addition, the metal ions are oxidized and precipitated with metal hydroxides such as Fe (OH) ₃ to cause reddish brown or white precipitates on the bottom of the river (yellow boy phenomenon) to harm the aesthetics.

Accordingly, in the passive treatment of the mine drainage, the oxidation tank is disposed at the entrance of the mine drainage discharged from the abandoned mine to precipitate iron from the acid mine drainage.

Divalent iron ions are oxidized and precipitated in the form of hydroxide as shown in the following scheme.

4Fe ^{2 +} + O ₂ + 4H ⁺ → 4Fe ^{3 +} + 2H ₂ O

Fe ^{3 +} + 3H ₂ O → Fe (OH) ₃ (s) + 3H ⁺

As described above, iron ions in the mine drainage must react with atmospheric oxygen or dissolved oxygen in the mine drainage for a sufficient time to precipitate into the hydroxide. And when the pH of the mine drainage is higher than the case where the pH is low, for example, the precipitation reaction rate is increased at pH 3 or more.

However, as described in the prior art, if the time for which the mine drainage dwells in the oxidizing tank is short, a sufficient reaction does not occur and a large amount of iron ions may be contained in the mine drainage discharged from the oxidizing bath. In addition, the pH of the mine drainage is low, the precipitation reaction rate is low, there is a problem that the iron removal efficiency falls.

Various problems arise when the mine drainage is subsequently processed without iron being removed.

For example, SAPS (Successive Alkalinity-Producing systems) forms an organic material layer and a limestone layer at the rear end of the oxidation tank, the iron ions in the mine drainage precipitates into the limestone layer, causing problems that lower the permeability of the limestone layer.

The present invention provides an oxidation bath that not only raises the pH of the mine drainage, but also allows the mine drainage to remain for a sufficient time so that the iron ions in the mine drainage can be effectively precipitated.

Hereinafter, with reference to the accompanying drawings, it will be described in more detail with respect to the oxidation tank for mine drainage treatment according to an embodiment of the present invention.

FIG. 8 is a schematic plan view of an oxidation tank for mine drainage treatment according to a first embodiment of the present invention, and FIG. 9 is a schematic sectional view taken along line VII-VII of FIG. 8.

8 and 9, the oxidation tank for mine drainage treatment is a kind of tank for depositing iron in the mine drainage while temporarily receiving the mine drainage leaching from the abandoned mine, which is disposed adjacent to the abandoned mine. Accordingly, the oxidation tank 100 according to the present invention includes an inlet portion 11 through which the mine drainage is introduced, a water tank 12 through which the mine drainage remains, and an outlet 13 through which the mine drainage is discharged.

In Korea, there is no water tank that can be used in a natural state on the topography, so it is common to artificially form a water tank with concrete, etc., but in many countries, a natural water tank is used as it is as an oxidation tank.

In the present invention, the neutralizer 30 is installed to increase the pH of the mine drainage introduced through the inlet 11. Various materials may be used as neutralizers for neutralizing acidic acid mine drainage, but limestone is used in this embodiment to raise the pH of the mine drainage to at least 3 or more. In this way, limestone is added to the water tank 12 to increase the pH of the mine drainage, thereby accelerating the iron precipitation reaction.

In the conventional treatment tanks such as SAPS, the limestone layer is formed on the bottom surface of the tank to allow the mine drainage to pass through the limestone layer in a downward flow. However, in the structure of SAPS, iron hydroxide precipitated from mine drainage could not be coated on limestone, or the mine drainage could not flow because the pores between limestones were filled.

Accordingly, in the present invention, in order to solve this problem, a method of suspending the neutralized body 30 including limestone in the water tank 12 is adopted. That is, by hanging the neutralized in water it is possible to prevent the iron hydroxide is coated on the neutralized by the flow rate. There are various ways to suspend the limestone neutralizer 30 in water. In this embodiment, the support member 35 is installed on the upper portion of the water tank 12, and a connection member such as a rope on which the mesh bag 37 is attached ( 36) to the support 35. Then, the limestone neutralizer 30 is placed in the mesh bag 37 so as to be in contact with the limestone neutralizer 30 while the mine drainage flows. Of course, a method of directly connecting a limestone neutralizer to a connection member without a structure such as a mesh bag may also be employed.

In addition, the neutralizer 30 may be configured in various forms. In the first embodiment illustrated in FIG. 9, a natural limestone mass is used.

In selecting the shape of the neutralizing body 30, two points should be noted. In other words, whether the iron hydroxide is effectively coated on the neutralizer is important, and whether the neutralization can be smoothly performed by increasing the contact area with the mine drainage.

Accordingly, the neutralizers 40 and 50 employed in the second embodiment shown in FIG. 10 and the third embodiment shown in FIG. 11 are configured in consideration of the above two aspects.

That is, referring to FIG. 10, the neutralizing body 40 employed in the second embodiment forms limestone into very small fine powders 41, and then fines the fine powders into a single mass using a coagulant 42. Formed. And the flocculant 42 selects a material that can be dissolved at a constant rate over time in the mine drainage. Since the coagulant 42 is dissolved at a constant solubility, the iron hydroxide is not coated on the neutralizer 40, and the limestone fine powder 41 is released into the mine drainage by dissolving the coagulant 42. The surface area is much greater than the volume of limestone masses, which can quickly increase the pH of the mine drainage.

11, the neutralizer 50 employed in the third embodiment pressurized the limestone mass to form fine cracks 51. More specifically, cracks are generated by pressing the limestone mass using a three-axis compressor. When the limestone in which the microcracks 51 are formed is suspended in the water tank 12, mine drainage flows into the gaps of the microcracks 51 to separate the small pieces of limestone. This can solve the problem that the iron hydroxide is coated on the limestone surface, and as the fine limestone pieces are introduced into the mine drainage, it can effectively increase the pH of the mine drainage.

In addition, the limestone neutralizing bodies 30, 40, and 50 employed in the first to third embodiments are disposed close to the inlet portion 11 in the water tank 12. This is because near the inlet 11, the flow rate is relatively high to prevent iron hydroxide from being coated on the neutralizer, and it is effective to increase the pH of the mine drainage at the inlet because iron tends to precipitate rapidly.

In addition, in another embodiment of the present invention, as described above, the side wall of the water tank 12 may be made of limestone without providing a separate neutralizer.

So far, the neutralizers 30, 40, and 50 are installed in the water tank 12 to increase the pH of the mine drainage, and thus the configuration for increasing the iron precipitation reaction rate has been described. Various types of dispersion guide members 110, 120, 130, 140, and 150 are provided to allow the drainage to stay in the tank 12 for a sufficient time.

The dispersion guide member is disposed at the inlet 11 of the tank 12 so that the mine drainage introduced through the inlet 11 is dispersed throughout the tank 12 so that the mine drainage can remain in the oxidation tank for a sufficient time. To help.

As described above, in the conventional oxidation tank, the mine drainage flows only in the direct direction connecting the inlet and the outlet, and no flow of the mine drainage is formed in the side of the oxidation tank. In addition, the mine drainage only moved to the surface of the oxidizing tank, and no flow was formed in the core.

Accordingly, the dispersion guide member employed in the present invention extends the residence time of the mine drainage while forming the flow of the mine drainage to the portion where the flow is not formed in the existing oxidation tank so that the entire region of the oxidation tank is used.

Therefore, the basic action of the dispersion guide member is summarized into three. First, the dispersion guide member is disposed in front of the inlet to allow a large amount of the mine drainage introduced into the inlet to enter the lower portion of the water tank. Second, compared with the direct direction connecting the inlet and outlet of the oxidizing tank, a relatively large amount of mine drainage is introduced in the bypass direction crossing the direct direction. Third, even in the bypass direction, a greater amount of mine drainage flows in the bypass direction formed at a greater angle with the direct direction.

The specific shape of the dispersion guide member for performing the above-described operation is various, first, the specific configuration of the dispersion guide member shown in FIG.

12, the dispersion guide member 110 includes a fitting plate 111, a semicircular partition wall 112, and a blocking plate 113.

The fitting plate 111 is a portion to be fitted to the inlet portion 11 of the oxidizing tank. In the present embodiment, since the inlet portion 11 is formed in a tubular shape, the fitting plate 111 has an arc-shaped fitting portion 114 at the top. Is formed and fitted to the inlet 11.

And the semi-circular partition wall 112 is arranged to surround the inlet 11, to block the path of the mine drainage flowed into the inlet. In the present embodiment is formed in a substantially semi-circular plate shape, both ends of the partition wall 112 is configured to be connected to both ends of the fitting plate 111, respectively. The semicircular partition wall 112 is disposed at or slightly higher than the surface of the mine drainage filled in the tank, and the lower part of the semicircular partition wall 112 is locked in the tank.

The length of the lower portion of the semi-circular partition wall 112 is formed to become shorter gradually from the center portion to the side portion. Here, the center portion of the partition wall 112 means a portion placed on a path along a direct direction connecting the inlet portion 11 and the outlet portion 12 of the oxidation tank. Or it may be a part placed on the path along the inflow direction of the mine drainage. Or it may be a part placed on the path along the main flow direction in the existing oxidation tank.

In addition, the side part of the partition 112 here means the part put on the path | route along the direction crossing with the said direct direction. In the present embodiment, the most protruding portion in the semicircular shape of the partition wall 112 is the center portion, and the portion adjacent to the fitting plate 111 is the side portion.

As shown in FIG. 12, the length of the lower portion is gradually shortened toward both sides from the center portion of the semicircular partition wall 112. Accordingly, the mine drainage introduced through the inlet 11 may be introduced in a relatively large amount in the bypass direction compared to the direct direction. In addition, as the lower length of the direct direction is formed longer, the mine drainage may be introduced into the lower portion of the water tank 12 rather than the top of the water tank 12.

Meanwhile, in the present embodiment, the blocking plate 113 is installed between the inlet portion 11 and the semicircular partition wall 112. When the blocking plate 113 is installed, the path of the mine drainage introduced from the inlet portion is blocked by the barrier plate 113 before the partition wall 112, and the blocking plate 113 assists the mine drainage to be distributed more efficiently. It plays a role.

The frame 115 is provided to install the fitting plate 111, the semicircular partition wall 112, and the blocking plate 113 in the water tank 12. The lower end of the frame 115 is supported on the bottom of the water tank 12, the fitting plate 111 and the partition 112 is fixed to the frame 115 by welding or the like.

Dispersion effect of the dispersion guide member 110 of the above configuration was installed in the stone rod oxidizing tank and tested.

FIG. 13 is a photograph experimenting with the present invention, in which the dispersion guide member is installed in the stone rod oxidizing tank (right side), and the photograph (left) in which the dispersion guide member is not installed.

And (a) of Fig. 13 is a state before the start of the experiment, (b) is a state after the injection of the dye 1 minute after starting the experiment, (c) is a state 2 minutes after the start of the experiment. And (a) of FIG. 14 is a state 10 minutes after dye injection, and (b) is a state after 20 minutes. 15 is a table showing the change in electrical conductivity with time at the inlet and outlet of the oxidation tank.

As shown in FIG. 13, when the dispersion guide member is not installed, the flow of the mine drainage appears linearly from the inlet to the outlet direction, whereas after the dispersion guide member 110 is installed, a specific flow direction does not appear and is oxidized. You can see that it is dispersed throughout the tank. And, it can be seen that air bubbles are generated around the vortex formed after the collision with the dispersion guide member at the inlet of the oxidation tank moves to the lower end of the dispersion guide member.

This tendency becomes apparent as the dye is added. As shown in (c) of FIG. 13, when the dispersion guide member is not installed (left side) two minutes after the dye is added, the dye has already arrived at the outlet, whereas after the dispersion guide member is installed, the dye is around the inlet. It can be seen that the mine drainage evenly spreads throughout the oxidizing tank.

Referring to FIG. 14, in the case where the dispersion guide member is installed, 10 to 20 minutes after the dye is added, it can be confirmed that the dye spreads to the left and right of the oxidation tank. After 20 minutes in this state, that is, about 40 to 50 after the dye is added It was confirmed that the dye is evenly discharged to the outlet portion in about a minute.

On the other hand, in order to accurately obtain the results of the above experiment, a diver was installed at each of the inlet and the outlet of the oxidizing tank, and salt water was added to the inlet to measure the residence time of the mine drainage. The results are shown in FIG. 15 is a table showing a change in electrical conductivity with time at the inlet and outlet of the oxidation tank. Referring to the table of FIG. 15, the time of first inputting brine from the inlet of the oxidizing tank is 886 seconds, and the time taken for the brine to reach the outlet due to a sudden change in electrical conductivity is estimated to be 3,877 seconds. As a result, the time taken from the inlet to the outlet is 2,991 seconds, which means that 49.9 minutes are required. This is an increase of about 11.5 times the residence time compared to the existing 4.35 minutes.

Table 1 below is a table comparing the performance of the mine drainage in the oxidation tank before and after the dispersion guide member is installed. As shown in the table, when the dispersion guide member is not installed, the nominal residence time and the measurement residence time ratio is very small at 4.3%, but after the dispersion guide member is installed, it is 49.9%, which corresponds to half of the nominal residence time. In addition, it can be seen that the residence time is improved by 11.5 times.

Properties
Dispersion guide member not installed
Dispersion guide member installation
Installed / not installed

Nominal residence time
N (min)
100
100
1.0
Measurement residence time
M (hr)
4.35
49.9
11.5
M / N (%)

4.3
49.9
11.6

As can be seen from the above experiments, after the dispersion guide member is installed, in the oxidation tank, the mine drainage flows evenly along the side and the bottom of the oxidation tank, which was the existing stagnant zone, so that the residence time is increased, so that the railway within the mine drainage is sufficiently settled and removed. It is effective.

The dispersion guide member 110 illustrated in FIG. 12 has been described so far, and a description will be given of another type of dispersion guide member with reference to the accompanying drawings.

16 to 18 show another type of dispersion guide member.

Referring to FIG. 16, the configuration of the fitting plate 121, the blocking plate 123, and the frame 125 in the dispersion guide member 120 is the same as that of the dispersion guide member 110 illustrated in FIG. 12, but The lower length of the semi-circular partition wall 122 is different in that it is constant. Instead of having a constant length of the partition wall 122, a plurality of discharge ports 126 are formed in the partition wall 122. The plurality of discharge ports 126 are for discharging the mine drainage, and the areas of the discharge holes 126 are formed differently for each position of the partition wall 122.

That is, the sum of the areas of the discharge holes formed in the upper part of the partition wall 122 is smaller than the sum of the areas of the discharge holes formed in the lower part of the partition wall, and the sum of the area of the discharge holes formed in the side of the partition wall 122 is formed in the center of the partition wall 122. It is larger than the sum of the discharge port areas. In addition, the area of the discharge port is gradually increased toward the side of the partition wall 122.

Eventually, the mine drainage is introduced in the bypass direction relatively more than the direct direction in the oxidizing tank, more can be introduced into the lower than the top of the oxidizing tank, after all the mine drainage can be evenly distributed throughout the oxidizing tank.

And the discharge port formed in the center of the discharge port 126 formed in the partition wall 122 is in the direct direction, the discharge port formed in the side is in the bypass direction, in order to ensure the direction of the mine drainage discharged through each discharge port The form shown in FIG. 17 is disclosed.

Referring to FIG. 17, the dispersion guide member 130 has the same configuration as that shown in FIG. 16, except that the discharge pipe 137 is coupled to each discharge port. That is, in the form shown in FIG. 16, the discharge pipe 137 is attached along the direction in which the discharge port 126 is formed to improve the directionality of the mine drainage discharged through the discharge hole. And, the length of the discharge tube provided in the lower part and the side of the partition 132 of the plurality of discharge tube 137 is formed longer than the discharge tube formed in the upper and center portion. Since the diameter of the discharge tube is the same as the diameter of the discharge port, the diameter of the discharge tube formed in the lower part and the side part of the partition 132 is naturally larger than the discharge tube formed in the center part and the upper part. Reference numerals 131, 133, and 135 which are not described in FIG. 17 are fitting plates, blocking plates, and frames, and thus the structure and operation of the dispersion guide member described with reference to FIG. 12 are the same.

Meanwhile, referring to FIG. 18, the fitting plate 141, the blocking plate 143, and the frame 145 in the dispersion guide member 140 have the same configuration as the previous embodiment. However, the semicircular partition wall 142 is different in that the plurality of through-holes are formed in a mesh.

That is, the semi-circular partition wall 142 is woven in a mesh by the horizontal line and the vertical line, a plurality of through holes are formed between the horizontal line and the vertical line, the mine drainage is discharged through these through holes.

In the partition wall 142 of the dispersion guide member 140 shown in FIG. 18, the horizontal portion and the vertical string are arranged more tightly in the center portion than in the side portion, and the upper portion is more tightly woven than the lower portion, so that the area of the through hole is narrower. . As a result, the mine drainage is more introduced into the side and bottom of the oxidizing tank, the mine drainage can flow through the oxidation tank.

The various types of dispersion guide members 110, 120, 130, and 140 have been described so far, but these are just examples, and the height of the partition wall and the direction and size of the discharge port may be slightly different with respect to the shape of the oxidation tank and the main flow direction of the oxidation tank. have.

In the above embodiments, all of the barrier ribs have been described as being formed in a semi-circular shape.

19 is a schematic perspective view of a new type dispersion guide member.

The dispersion guide member 150 shown in FIG. 19 is also installed in front of the inlet 11 of the oxidizing tank, and serves to guide the flow of the mine drainage flowing through the inlet 11 in a different direction.

That is, the mine drainage flowing through the inlet portion in a normal oxidation tank is generally designed to face the outlet portion. The dispersion guide member 150 crosses the flow of the mine drainage with a direct direction connecting the inlet portion and the outlet portion. Ie guide in the bypass direction.

In this embodiment, the dispersion guide member 150 has a first wing surface 151 and a second wing surface 152 formed in a plate shape. The first wing surface 151 and the second wing surface 152 is formed in a curved surface to guide the mine drainage introduced into the inlet 11 in the left and right directions of the inlet 11, respectively, to the entire oxidation tank. Induce to be distributed.

In addition, the upper portion of the dispersion guide member 150 protrudes toward the inlet portion than the lower portion, the mine drainage introduced into the inlet portion is naturally guided to the lower portion of the tank so that the mine drainage can also flow through the lower portion of the oxidation tank.

In addition, the first wing surface 151 and the second wing surface 152 are not necessarily to be symmetrical, and may not be symmetrical with respect to the shape of the oxidation tank and the main flow direction. The angle of the two wing surfaces 152 and the inflow direction of the mine drainage may also vary depending on the shape and conditions of the oxidation tank.

The performance of the dispersion guide member 150 shown in FIG. 19 was tested. FIG. 20 is a photograph showing an experimental process of the dispersion guide member illustrated in FIG. 19 over time, and FIG. 21 is a table illustrating a change in electrical conductivity with time at an inlet and an outlet of an oxidizing tank.

Referring to FIG. 20, when the dispersion guide member 150 is installed, it can be seen that the dye injected into the inlet is dispersed throughout the oxidation tank over time. In contrast, when the dispersion guide member is not provided as shown in FIG. 4, the dye forms a linear flow from the inlet to the outlet.

10 minutes after the dye was added, it was mainly distributed in the left and right sides of the oxidizing tank, and gradually spread to the center of the oxidizing tank, and after 20 minutes after the dye was introduced, it was confirmed that the process of being discharged to the outlet part was diffused to the entire oxidizing tank.

In addition, a diver was installed at the inlet and outlet of the oxidizing tank to accurately measure the residence time of the dye. Brine was added as a tracer to the mine drainage inlet, and the residence time was measured. The results are shown in the table of FIG. Referring to FIG. 21, the time at which the brine was introduced at the inlet was 514 seconds, and the time at which the brine reached the outlet was 3,066 seconds due to the change in electrical conductivity at the outlet. A total of 2,552 seconds can take 42.5 minutes. As a result, it can be seen that the residence time of the mine drainage is significantly increased compared to the conventional oxidation tank.

Table 2 below compares the performance of the oxidizing tank when and without the dispersion guide member shown in FIG. As shown in Table 2, when the dispersion guide member is not installed, the nominal retention time and the measurement residence time ratio are very small at 4.3%. However, when the dispersion guide member is installed, the dispersion guide member is greatly increased to 42.5%. This is an improvement of the existing residence time by 9.8 times.

Properties

Dispersion guide member not installed
Dispersion guide member installation
Installed / not installed
Nominal residence time, N
(min)
100
100
1.0
Measurement residence time, M
(hr)
4.35
42.5
9.8
M / N (%)

4.3
42.5
9.9

As described above, in the present invention, by installing a dispersion guide member capable of dispersing the flow of the mine drainage at the inlet of the oxidation tank, the mine drainage can flow through the entire oxidation tank. More specifically, in the conventional oxidation tank, the mine drainage flowed in the direct direction connecting the inlet and the outlet and only through the upper part of the oxidation tank. The flow was formed to extend the residence time of the mine drainage.

As the residence time in the oxidation tank of the mine drainage increases, the mine drainage reacts with oxygen for a sufficient time so that iron ions in the mine drainage can be removed by being precipitated to the bottom of the oxidation tank.

As described above, the present invention improves the precipitation reaction rate by increasing the pH of the mine drainage by using a neutralizer, and at the same time increases the residence time in the tank of the mine drainage so that the iron precipitation reaction can occur sufficiently, Most of the iron ions in the drain can be removed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation and that those skilled in the art will recognize that various modifications and equivalent arrangements may be made therein. It will be possible. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

100 ... oxidation tank for mine drainage treatment ...
12 ... water tank 13 ... outlet
30,40,50 ... neutralizer 41 ... fine powder
42 ... flocculant 51 ... crack
110,120,130,140,150 ... dispersion guide member

Claims (16)

An inlet portion into which the mine drainage flows, a water tank into which the mine drainage flowed into the inlet portion stays, and an outlet portion from which the mine drainage in the tank is discharged, so that the iron in the mine drainage remains in the tank while In the oxidation tank for mine drainage treatment to be oxidized and precipitated,
Oxidation tank for treatment of mine drainage, characterized in that the neutralization body for accelerating the iron precipitation reaction by increasing the pH of the mine drainage. The method of claim 1,
The neutralization body is an oxidation tank for mine drainage treatment, characterized in that suspended in the water of the tank. The method according to claim 1 or 2,
The neutralizer is an oxidation tank for mine drainage treatment, characterized in that the natural limestone mass. The method according to claim 1 or 2,
The neutralizing body includes a limestone fine powder and a flocculant for forming the limestone fine powder into one mass,
The limestone fine powder is in contact with the mine drainage while the coagulant is dissolved in the mine drainage. The method according to claim 1 or 2,
The neutralizing body is an oxidation tank for the mine drainage treatment, characterized in that the limestone agglomeration in which a plurality of cracks are formed by pressing. The method of claim 1,
Oxidation tank for mine drainage treatment, characterized in that the wall surface of the tank is made of limestone. The method of claim 1,
And the neutralizing body is disposed closer to the inlet than the outlet. The method of claim 1,
The oxidation tank for mine drainage treatment, characterized in that it further comprises a dispersion guide member which is installed in front of the inlet portion to form a flow in a form distributed in the water tank through the inlet portion. The method of claim 8,
The dispersion guide member,
Compared to the direct direction connecting the inlet and the outlet, a relatively large amount of mine drainage flows in the bypass direction crossing the direct direction,
To allow a relatively large amount of mine drainage flows in the bypass direction forming a relatively large angle with the direct direction,
Oxidation tank for mine drainage treatment, characterized in that to allow a relatively large amount of mine drainage flows into the lower side than the upper side of the tank. The method of claim 8,
The dispersion guide member,
It is formed in a curved plate shape is installed in the tank surrounding the inlet, thereby blocking the flow of the mine drainage,
The oxidation tank for mine drainage treatment, characterized in that the lower length of the portion blocking the mine drainage discharged along the bypass direction formed at a relatively large angle with the direct direction connecting the inlet and the outlet is formed relatively long. The method of claim 8,
The dispersion guide member,
It is formed in a curved plate shape is installed in the tank surrounding the inlet, thereby blocking the flow of the mine drainage,
The dispersion guide member is formed with a plurality of discharge holes for discharging the mine drainage, the sum of the discharge port area formed on the lower surface of the dispersion guide member is larger than the sum of the discharge holes formed on the upper surface,
Mine drainage, characterized in that the sum of the discharge port area formed along the bypass direction which has a relatively large angle difference with the direct direction connecting the inlet and the outlet is larger than the sum of the discharge port area when the angle difference is relatively small. Oxidation bath for treatment. The method of claim 11,
And each discharge port is provided with a discharge tube for guiding the mine drainage along the direction of the discharge port. The method of claim 12,
Among the discharge tubes, the discharge tube disposed below the dispersion guide member is formed longer than the discharge tube disposed above.
The oxidation tank for mine drainage treatment, characterized in that the length of the discharge tube formed along the bypass direction having a relatively large angle difference with the direct direction is longer than the length of the discharge tube when the angle difference is relatively small. The method of claim 1,
The dispersion guide member,
Oxidation tank for mine drainage treatment characterized in that it is formed in a plate shape along the bypass direction intersecting the direct direction connecting the inlet and outlet, and guides the flow of the mine drainage flowed into the inlet. The method of claim 14,
A first wing surface formed of a curved surface, and a second wing surface coupled to the first wing surface and formed symmetrically with the first wing surface,
The mine drainage treatment is an oxidation tank for mine drainage treatment, characterized in that the dispersion in the opposite direction along the first wing surface and the second wing surface. The method of claim 14,
The dispersion guide member is formed so that the upper portion is projected toward the inlet portion compared to the lower portion so that the mine drainage is guided toward the lower portion of the tank.

Images